// GLib.Idle.cs - Idle class implementation
//
// Author(s):
//	Mike Kestner <mkestner@speakeasy.net>
//	Rachel Hestilow <hestilow@ximian.com>
//	Stephane Delcroix <stephane@delcroix.org>
//
// Copyright (c) 2002 Mike Kestner
// Copyright (c) Rachel Hestilow
// Copyright (c) 2009 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the Lesser GNU General 
// Public License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.


namespace GLib {

	using System;
	using System.Collections.Generic;
	using System.Runtime.InteropServices;

	public delegate bool IdleHandler();

	public class Idle {

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		delegate bool IdleHandlerInternal();

		internal class IdleProxy : SourceProxy {
			public IdleProxy(IdleHandler real) {
				real_handler = real;
				proxy_handler = new IdleHandlerInternal(Handler);
			}

			public bool Handler() {
				try {
					IdleHandler idle_handler = (IdleHandler)real_handler;

					bool cont = idle_handler();
					if (!cont) {
						lock (this) {
							Dispose();
						}
					}
					return cont;
				} catch (Exception e) {
					ExceptionManager.RaiseUnhandledException(e, false);
				}
				return false;
			}
		}

		private Idle() {
		}

		[DllImport(Global.GLibNativeDll, CallingConvention = CallingConvention.Cdecl)]
		static extern uint g_idle_add_full(int priority, IdleHandlerInternal d, IntPtr data, DestroyNotify notify);

		public static uint Add(IdleHandler hndlr) {
			IdleProxy p = new IdleProxy(hndlr);
			lock (p) {
				var gch = GCHandle.Alloc(p);
				var userData = GCHandle.ToIntPtr(gch);
				p.ID = g_idle_add_full(0, (IdleHandlerInternal)p.proxy_handler, userData, DestroyHelper.NotifyHandler);
			}

			return p.ID;
		}

		public static void Remove(uint id) {
			Source.Remove(id);
		}
	}
}